Austin o



Feb. 3, 19316 COQLEY 1,791,053

PHQTOGRAPHIC EMULSION FOR ELECTRONIC DISCHARGE Filed June 7, 1928 SENS/T1250 EMULSION CONTAIN/N6 'METALL/G A T/045s EMULSION SUPPORT Patented Feb. 3,1931

UNITED STATES AUBTING. COOLEY, OF NEW YORK, N. Y.'

raoroemnrcnmursron m ELECTBQNIG mscnanen Application filed June 7, 1928. Serial 1%. 283,474.

In myprior Patent No. 1,702,595 granted Feb. 19, 1929, I have disclosed a new method of recording printed matter pictures, etc., which consists in modulating high-frequency 5 oscillations in accordance with the photographic subject matter, or other sub ect matter such for example as printed matter, and effecting the photographic exposure upon an ordinary photographic emulsion or other suitable receivin or reproducing medlum with an electric ischarge produced by the oscillations. Relative movement may be produced between the discharge and the receiving or reproducing medium, in any suitable manner. For example, the reproducing medium may be rotated on a drum or dis and the electrical discharge caused to trace over the medium along arallel lines constituting a spiral. The e ectrical discharge is preferably in the form of a corona discharge which pulsates at a predetermined frequency, either ceasing entlrely between beats or decreasing to an intensity s0 1ow as to aflect the reproducing medium little 1f any, thereby forming a succession of dots or short dashes on the medium. The beats, which are modulated in accordance with the subject matter, are impressed upon hlgh-frequency oscillations which are adapted to produce the corona effect without dlsruptive discharge.

The oscillating circuit s preferably ad usted to generate oscillations of high-frequency and high-potential adapted to produce anelectronic discharge from a needle electrode adjacent to but preferably spaced slightly from the photographic paper upon which the record is to be made, the discharge being emitted when the oscillation intensity is high- 40 er than that existing between successive impulses of the transmitted subject matter, the intensity of the discharge depend ng upon the exent of the oscillation intensity above predetermined intensity, whereby an electronic discharge is emitted from the needle during impulse (except perhaps while re-- cording a white or an extremely light representation on the receiving paper). Thus, in transmitting a half-tone, a dot (or short dash) is recorded on the receiving paper at each impulse, the dot varying in intensity in response to variations in the intensity of said impulses, and in transmitting extreme contrasts such as the black and white of printed matter, at each impulse during assage of black or white (depending upon t e adjustment of the transmitting apparatus as described in the above patent past the oint of incident of the pencil of. ight whic traces the subject matter to be'transmitted at the transmitting station.

The recording paper may be of the type requiring development subsequent to exposure by the corona discharge to convert the latent image into a visible image, or it may be of the type in which a visible image is produced without development, the latter type having the advantage of displaying the image as it is recorded. The corona discharge produces the exposure rimarily by electronic bombardment of t e photographic emulsion, assisted to some extent by light and/or heat. If the recording medium is of the type adapted to be affected by the corona discharge independently of the light produced thereby, the paper may be enclosed in an opaque envelope or tuned over and the process performed in a lighted room, or a plurality of superposed sheets may be exposed simultaneously; and if the recording medium be of e the type which is sensitive to the corona discharge but insensitive to light, the process may be carried out in a lighted room without protecting the medium with an opaque covermg.

This invention relates to the recording paper or sensitized emulsion and has for its objects to intensify the exposure, particularly when efiected by a corona discharge as above described, so that the desired degree of exposure may be efiected with a weaker discharge, and to produce a smoother and more attractive print.

' According to this invention finely divided metallic or other conducting particles are incorporated in the emulsion, preferably separated from one another b the gelatin or other material of the emulsion, for the purpose of increasing the potential gradient through the emulsion (between the aforesaid needle and a drum or other metallic support for the paper connected to the other side of the circuit as described in said patent), thereby making the emulsion more sensitive to a. corona discharge of predetermined value. The presence of the finely divided metallic particles will also tend to diffuse the discharge, thereby aflordin a smoother print. By employing a metal W ich is a catalyst or chemical reagent (e. g. magnesium) the effect of the exposure may be still further intensified.

I claim:

A photographic coating sensitive to electronic discharge therein characterized by finely divided conducting particles distributed therethrough.

Signed by me at New York, New York, this second day of June, 1928.

AUSTIN G. COOLEY. 

